Forklift trucks come in many sizes and capacities and are typically powered using batteries, gasoline, diesel fuel, or liquid propane. Typically, forklift trucks powered by liquid propane (“LP”) fuel are equipped with a removable fuel tank, which generally is constructed from steel or aluminum and weighs from 33.5 lbs when empty to 88 lbs when full. The fuel tank is typically secured to the forklift truck on a fuel tank bracket mounted on or near a counterweight at the truck's rear. The tank bracket ensures that the fuel tank remains relatively immobile during truck operation.
This placement often means that the tank bracket is positioned at or above an operator's chest level and up to an arm's length away. Thus, to load a fuel tank onto or off of the tank bracket, the operator is required to lift the fuel tank up above the counterweight and reach over part of the length of the counterweight. Because a full or substantially full fuel tank can be quite heavy, loading and unloading a fuel tank can be dangerous and may subject an operator to injury. In order to relieve some of the burden on the operator, some tank brackets are designed to provide an operator with assistance in the loading and unloading of the fuel tank.
Generally, a tank bracket designed to provide operator assistance includes a frame mounted on the forklift truck and a cradle pivotally connected to the frame via one or more pivots. The frame secures the tank bracket to the forklift truck, and the cradle supports the fuel tank. Typically, the cradle is maneuverable between two positions. In the first position, referred to herein as a “retracted position,” the fuel tank is immovably locked onto the forklift truck by a latching mechanism. Typically, when the tank bracket is in the retracted position, the cradle lies inside the truck's body frame above the counterweight. In the second position, referred to herein as an “extended” position, the fuel tank may be more easily loaded onto and unloaded off of a forklift truck. Typically, when a tank bracket is in an extended position, the cradle lies outside the truck's body frame to the rear or a side of the counterweight.
To maneuver the cradle between the retracted and extended positions, the cradle is pivotally rotated using one or more stages. For example, a cradle moved from a retracted position to an extended position using one stage is typically rotated in a plane substantially parallel to the top surface of the counterweight about a single pivot using a single rotational motion. A tank bracket having a cradle moved to an extended position using a single stage is referred to as a “single stage” tank bracket. A cradle moved from a retracted position to an extended position using two stages may be rotated in a horizontal plane that is substantially parallel to the counterweight's top surface about a first pivot using a first motion and then rotated in a vertical plane that is substantially parallel to the counterweight's rear surface about a second pivot using a second motion. A tank bracket having a cradle moved to an extended position in two stages is referred to as a “two-stage” tank bracket.
FIGS. 1-3 show typical tank brackets designed to provide loading and unloading assistance. FIGS. 1 and 2 show typical designs for a single stage tank bracket, and FIG. 3 shows a typical design for a two-stage tank bracket.
FIG. 1 shows a diagram of a forklift truck (100) equipped with a prior art tank bracket (106). The tank bracket (106), which is mounted on forklift truck's counterweight (104), includes a frame (108) attached to the forklift truck (100), a cradle (110) rotatably connected to the frame (108) via a pivot (112), and a strap (114) connected to the cradle (110). A fuel tank (102) is disposed within the cradle (110), and the strap (114) is engaged around an uncovered portion of the fuel tank's circumference so that the fuel tank (102) does not fall out of the cradle (110). Further, the cradle (110) is shown in an extended position, and, accordingly, sits behind the counterweight (104) and outside the truck's body frame.
To maneuver the cradle to the retracted position, the cradle (110) is rotated about the pivot (112) such that the cradle (110) moves inward to a position above the counterweight (104) and inside the truck's body frame. Note that, in this tank bracket (106), the cradle (110) is rotated between the retracted and extended positions using a single motion. Because the cradle (110) may be rotated from the retracted position to the extended position using a single outward motion, tank bracket (106) is often referred to as a “swing out” fuel tank bracket.
FIG. 2 shows a diagram of a forklift truck (200) equipped with another prior art tank bracket (206). The tank bracket (206) includes a frame (208) mounted on the truck's head guard (216) just above a counterweight (204). As shown in FIG. 2, the frame (208) is actually a pair of brackets, where a first bracket (218) is mounted on a left side of the head guard (216) and a second bracket (220) is mounted on a right side of the head guard (216). Further, a cradle (210) is rotatably connected to the first bracket (218) via a pivot (212), and a strap (214) connected to the cradle (210) is engaged around a fuel tank (202). In the view shown, the cradle (210) is in an extended position.
To maneuver the cradle (210) to the retracted position, the cradle (210) is rotated inward about the pivot (212) to a position above the counterweight (204) and inside the forklift truck's body frame. The cradle (210) is locked to the frame's second bracket (220) via a latching mechanism. Note that, in this tank bracket (206), the cradle (210) is rotated between the retracted and extended positions using a single motion. Because the cradle (210) may be rotated to the extended position using a single outward motion, the tank bracket (206) is often referred to as a “swing out” fuel tank bracket.
The tank brackets shown in FIGS. 1 and 2 reduce the reach required to install a fuel tank, thereby reducing the difficulty of installing a tank and reducing risk to the operator.
FIG. 3 shows a diagram of a forklift truck (300) equipped with a prior art two-stage tank bracket (306) designed to reduce both a height and a reach required to install a fuel tank. The tank bracket (306) includes a frame (308), a cradle (310), and a strap (316). As shown in FIG. 3, the frame (308) is actually a pair of brackets, where a first bracket (322) is mounted on a left side of the truck's head guard (320) just above a counterweight (304) and a second bracket (324) is mounted on a right side of the head guard (320) just above the counterweight (304). The cradle (310) supports a mounted fuel tank (302) and is rotatably connected to the second bracket (324) via a first pivot (312) and a second pivot (314). The strap (316) is connected to the cradle (310) and engaged around the fuel tank (302). In the view shown, the cradle (310) is in an extended position.
To maneuver the cradle (310) into a retracted position, the cradle is rotated using two motions. In a first motion, an operator rotates the cradle (310) upward about a second pivot (314) to a position above and substantially parallel to the top surface of the counterweight (304) and outside the truck's body frame. After the first motion, the cradle (310) is locked such that it may not rotate about the second pivot (314). Then, in a second motion, the operator rotates the cradle (310) inward across the counterweight's top surface to a position inside the truck's body frame. At the end of the second motion, the cradle (310) is locked to the frame's first bracket (322).
The tank bracket (306) shown in FIG. 3 also includes gas springs (318) (only one is visible in FIG. 3) that are connected to the frame (308) and the cradle (310). The pair of gas springs (318) is used to support a portion of the weight of the cradle (310) and fuel tank (302) when the cradle (310) is rotated downwardly. Thus, although a motion for maneuvering the cradle (310) about the first pivot (312) is manual, when the cradle (310) is maneuvered about the second pivot (314), the gas springs (314) help support the combined cradle (310) and fuel tank (302) weight. Note that, because the cradle (310) may be rotated to the extended position using two separate motions, an outward motion and then a downward motion, the tank bracket (306) is often referred to as a “swing out, swing down” fuel tank bracket.
As described above, the tank bracket (306) shown in FIG. 3 requires two stages to maneuver between the retracted and extended positions. In each of these stages, the cradle (310) moves in either a vertical direction or a horizontal direction.
What is still needed, therefore, is a tank bracket that makes the loading and unloading of a fuel tank much easier for an operator.